In many industries raw material is handled in panel or sheet form, hereinafter referred to as panelized material. In many of the woodworking and related trades the panelized material is often manufactured having dimensions of about four feet by eight feet and a thickness of about 1/4 ″ to about 1″. The panelized material is then cut to exact dimensions using various cutting equipment. The panelized material is typically rip-cut along the long dimension of the panelized material and cross-cut along the shorter dimension of the panelized material to make smaller pieces of material.
There are a number of machining methods and machines used to achieve this action of ripping and cross cutting of panelized material. Generally, this cutting action is performed on one or more specialized machines. The panelized material is typically ripped on a table saw and cross-cut on a radial arm saw. The table saw and the radial arm saw are well suited for each of these respective operations due to the layout of their guide mechanism.
The table saw usually has a guide mechanism, referred to as a fence, oriented parallel to the cutting plane of the blade. Material is fed into the machine along the fence so as to establish a constant width of the cut material. The material is supported in the horizontal plane by the primary table surface of the saw. This piece of equipment is well suited for cuts along the long axis of the panelized material or sheet good. Cutting across the short axis of a panel on a table saw can be a dangerous activity because there is a tendency for material to get jammed between the blade and the fence. This could result in a kick-back of material towards the operator which is clearly a dangerous situation.
After the material is ripped to a particular width on the table saw it is typically then transported to the radial arm saw for cross-cutting. The material is held stationary against a guide fence which is oriented perpendicular to the plane of the blade and the saw motor and blade assembly is actuated to travel across the material in an axis perpendicular to the guide fence. Again the panel is supported in the horizontal plane by the table structure of the radial arm saw. This process is repeated as necessary to cut the raw material panel into finished pieces of a specific length and width dimension. The radial arm saw has an associated safety issue. Since the motor and blade assembly combination travels on a track suspended above the panel being cut and the operation is performed by pulling the motor and blade assembly towards the operator from the resting position, there is tendency to over-feed during a cut, thereby causing the motor and blade assembly to aggressively move towards the operator.
The issues with these types of machines relate to material handling and operator safety. Manually feeding material into these machines can require more than one operator due to the weight and size of the panelized material. Additionally, there is an associated handling step between each machine to orient the panel through the sawing process. Also, handling of a panel while oriented in the horizontal plane can require considerable space and effort.
Another type of machine used for cutting panelized material to size is known as a vertical panel saw. This machine overcomes some of the issues having to do with material handling in the horizontal plane and the safety issues of material kick-back associated with using a table saw or radial arm saw. A near-vertical frame and a horizontal guide shelf are used to support the panelized material. The frame is approximately five to twenty degrees off of the vertical axis, thereby allowing gravity to naturally hold the panelized material in place. The guide shelf allows panels to be translated left or right and simplifies the loading and unloading process as well as the cutting process. The panel saw has a single electric motor with a circular cutting blade for cutting the panelized material.
The electric motor, through its housing, is fixed to a platform that translates on a pair of guide rails. The motor is rotatable on the platform between two positions. In the first position the cutting blade is oriented parallel to the guide rails and allows the panelized material to be cross-cut. During this cutting action the panelized material is held stationary on the panel saw frame and the operator slides the platform with the rotating cutting blade across the width of the panelized material. When the cut is completed, the operator must return the platform to a position towards the top of the panel saw in order to prepare the saw for cutting of another piece of material. In the second position the cutting blade is oriented parallel to the guide shelf and allows the panelized material to be rip cut. During this cutting action the platform with the electric motor and rotating cutting blade is locked to the guide rails and the operator slides the panelized material into the cutting blade.
The panel saw overcomes many of the safety issues of the table saw and radial arm saw and improves the material handling process by allowing the material to be worked in the near vertical orientation. However, a significant problem exists when trying to use this type of machine in situations that require a number of identical finished panels to be made. This situation occurs frequently when building a plurality of the same project or when building a project with duplicate components, for example, the ends, the sides, or the tops and bottoms of a box.
In existing panel saws only one dimensional value can be “set-up” at a time so as to cut only one pre-selected dimension. To cut numerous panels to the same dimensions, the operator could load the first panel on to the guide shelf, rip the panelized material to the first dimension, rotate the motor on the platform 90 degrees, set the second dimension, and then cross-cut the material. The operator would have to repeat this step for each additional panel. Resetting the machine from one dimension to another and back again invites deviations in dimensional values from one finished panel to the next.
Alternatively, the operator would have to rip all the panels to the first dimension, rotate the motor on the platform 90 degrees, and then reload all the panels back onto the guide shelf for cross cutting. This double handling problem adversely affects productivity.
Another variation of a panel saw is of a design often referred to as a “European style panel saw”. A vertical panel frame again is the central structure of the machine. A translating mechanism that spans the narrow axis of the machine is connected to an additional mechanism that allows the entire saw/motor mechanism to translate along the long (horizontal) axis of the machine. This essentially allows the motor and blade assembly to operate over two dimensions rather than one, translation in the horizontal and vertical axis. However, the motor and blade assembly still must be rotated to make the typical two cuts required to size a panel to a particular length and width. Also, the coupled translational mechanism used in this style machine greatly increases the machine's cost and complexity.
In these panel saws the means for setting a desired length and width of a panel could not be set simultaneously while allowing the machine to be used for cutting. Only one dimensional value could be selected at a time. This is because only a single cutter head was used to perform both dimensional cuts. Cutting in one axis precluded the other axis dimension from be locked into a preset.
In existing panel saw systems, the blade depth is fixed to its maximum depth and panels can only be fully cut starting at one edge.
Existing dust collection systems on panel saws require a vacuum line to emanate from the highest point in the z-axis of the motor and blade assembly. These systems tangentially collect dust off of the periphery of the blade. The dust collection port would then transition at least 90 degrees to a vacuum hose that would lead towards the top of the machine. This arrangement is generally in the path of the operator and can make operating the machine a bit awkward.
One of the dangers of operating a circular saw, or any cutting machine, is associated with continued operation after the cutting head or saw blade has become dull. Many power tools have significant warnings regarding operation with the use of dull cutting tools. Operation with dull tooling can lead to damage of the machinery and injury to the operator. The motor and drive components can be damaged from the overload conditions presented by continued operation with dull tooling. The operator can be harmed by the excessive forces required to push material through a machine with dull tooling. Additionally, attempting to force material through the cutting process when the cutting tool has become dull can result in the jamming and/or the kickback of the material being machined. All of these conditions increase the risk of injury to the operator.